In writer-director Jonathan Lisecki’s new film, Gayby, a frustrated Manhattan single recruits her gay male companion to have a baby with her. The twist? She insists they conceive the old-fashioned way. On paper, the movie seems like it might unfold like a half-baked Kissing Jessica Stein–style romp through the vagaries of human sexuality. But while Gayby does have a certain late-’90s indie feel to it, Lisecki has actually created a nutty, charming portrait of the ways sex can alter a totally platonic relationship.

The story was born from Lisecki’s musings on how he, a gay man, could have his own child without breaking the bank. Its marriage of wacky sexual hijinks and wry dialogue comes from his love of classic screwball comedies. “There’s something about movies from the ’30s and early ’40s, like Bringing Up Baby and His Girl Friday,” says Lisecki. “This is an homage to that freewheeling, fun comedy where everyone’s intelligent and no one’s a buffoon.”

It’s to Lisecki’s credit that Gayby contains such appealing and believable characters. Gay father-to-be Matt (Matt Wilkas) is a sad-sack comic book store owner still reeling from a six-year-old breakup, while his gal pal Jenn (Jenn Harris) is a sexually adventurous yoga instructor scared into her unconventional pregnancy by a string of short-term romances. Lisecki himself shows up, playing their bitchy wannabe-bear sidekick. Yet the palpable clumsiness of Wilkas and Harris’s sex scenes succeeds in part because the actors are longtime best friends in real life. They met in college, and Gayby opens with a montage of photos from their past, revealing years of embarrassing haircuts and a closeness that’s impossible to fake.

“I think our chemistry is not something you can reproduce,” says Wilkas. “Imagine having sex with your best friend. It’s more fun to do an awkward sex scene than a really sexy one.”